Preparation of a d-Glucose-Derived Alkene. An E2 Reaction for the Undergraduate Organic Chemistry Laboratory

Abstract

As the carbohydrates continue to gain attention for their central role in numerous areas of chemistry and biology, there is a growing need for experiments at the undergraduate level that highlight these fascinating compounds. In this article we describe a simple two-step laboratory experiment that may be used to highlight several important concepts introduced in sophomore organic chemistry, as applied to compounds of potential biological interest. The sequence begins with commercially available diacetone glucose, which is converted to the highly crystalline tosylate derivative. Upon treatment of compound 2 with potassium tert-butoxide in THF solution, the alkene (3-deoxy-1,2:5,6-di-O-isopropylidene-α-D-erythro-hex-3-enofuranose) is formed via an E2 reaction. The synthetic sequence allows for discussion of various concepts within organic chemistry, as well as for the application of analytical techniques such as polarimetry and one- and two-dimensional NMR.